updated CHANGELOG for 2.1.11
update CONTRIBUTORS for 2.1.11
updated VERSION for 2.1.11
Merge branch '2.1' into 2.2

* 2.1:
  updated VERSION for 2.1.11
  update CONTRIBUTORS for 2.1.11
  updated CHANGELOG for 2.1.11

Conflicts:
	src/Symfony/Component/HttpKernel/Kernel.php